The canonical prohibition of Catholic membership of a Masonic Lodge or society was expressly articulated in canon 2335 of the 1917 Code of Canon Law, with attached a penalty of excommunication, latae sententiae. Further canonical effects explicitly linked to Masonry were contained six additional canons spread throughout the Code.
The 1983 Code of Canon Law contains no explicit mention of Freemasonry. Canon 1374 provids for indeterminate penalties for those who joined societies which “plot against the Church”, but there is no consensus of what the canonical definition of plotting (machinationem) means, nor which societies, if any, might be intended by the canon.
This article traces the origins of the Church’s opposition to Freemasonry, along with the canonical provisions made against it, through the formulation of both Codes of Canon Law, and establishes the existence, necessity, and justice of an enduring universal canonical prohibition of Catholic membership of the Freemasons.